Drug Resistance in Newly Presenting and Previously Treated Tuberculosis Patients in Guangxi Province, People's Republic of China.

Drug-resistant Mycobacterium tuberculosis strains are a major threat to the control of tuberculosis (TB), but the prevalence of drug-resistant TB is still unknown in the southern ethnic region of China. A cluster-randomized sampling method was used to include the study population. Isolates were tested for resistance to 6 antituberculosis drugs, and genotyped to identify Beijing strains. Overall, 11.3% (139/1229) of new cases and 33.0% (126/382) of retreated cases had drug-resistant tuberculosis. Multiple previous TB treatment episodes and multiple treatment interruptions were risk factors for both drug-resistant and multidrug-resistant TB among retreated cases. A total of 53.2% of the patients were infected with a Beijing strain of M tuberculosis. Infection with a Beijing strain was significantly associated with drug resistance among new cases (odds ratio, 1.44; 95% CI, 1.01-2.07). Novel strategies to rapid diagnosis and effective treatment are urgently needed to prevent the development of drug resistance.

Interleukin-17 and the interleukin-17 family member network.

Interleukin-17 (now known as IL-17A), is a homodimer of two 155 amino acid chains secreted by CD4+ activated memory T cells (CD45+ RO+) and is available as a glycosylated 20- to 30-kDa homodimeric peptide. Human IL-17 shows amino acid sequence identity of 62.5 and 58% to the mouse and rat sequences, respectively. IL-17 can regulate the function of a variety of cell types, plays an important role in the maturation of hematopoietic progenitor cells, and induces production of proinflammatory mediators. Here, for the first time, we summarize the biological effects of IL-17 and its family members as important players of T cell-mediated immune responses and underline the important implications of this cytokine in inflammation and degenerative diseases.

[Effects of lead on thyroid function of occupationally exposed workers].

OBJECTIVE: To explore the effects of lead on the thyroid function of occupationally exposed workers. METHOD: 157 workers occupationally exposed to lead in a smelting factory were investigated. The concentration of lead in air at workshop was measured by flame atomic absorption spectrophotometry (FAAS) and the levels of blood lead (PbB) by atomic absorption spectrophotometry (AAS), zinc protoporphyrin (ZPP) by ZnPP meter, as well as the indexes of thyroid function, thyroid-stimulating hormone (TSH), triiodothyronine (T(3)), thyroxin (T(4)), free T(3) (FT(3)), and free T(4) (FT(4)) in serum by radioimmunoassay. RESULTS: The workers with higher level of blood lead (> 2.88 micro mol/L) showed lower levels of T(3) [(1.54 +/- 0.39) nmol/L] and FT(3) [(5.50 +/- 1.26) pmol/L] than those with lower blood lead level [PbB: (1.92 approximately 2.88) micro mol/L group, T(3): (1.71 +/- 0.45) nmol/L, FT(3): (6.12 +/- 1.64) pmol/L, P < 0.05]. There was no obvious effect of length of service on thyroid hormone of exposed workers. CONCLUSION: Higher level of blood lead may cause certain damage to thyroid function by inhibiting deiodination of T(4). No obvious relation between length of service and thyroid function was found.

[Immune responses of silicotic rats to the antigen of sheep red blood cells].

OBJECTIVE: To explore the immune response of silicotic rats to sheep red blood cells(SRBC). METHODS: Silicotic rats were immunized with SRBC by tracheal instillation(Group 1) or intraperitoneal injection (Group 2), and non-silicotic rats were immunized by tracheal instillation as normal control(Group 3). The levels of serum hemolytic index(HC50) were measured on 7, 12, 20, 25, and 32 days after primary immunization and 5, 12, 15 days after the second immunization. Special anti-SRBC IgG was measured with ELISA(A490 nm) on 12, 20, 25, 32 days and 5, 12, 15, 27 days respectively. Delayed-type hypersensitivity(DTH) to SRBC was measured 20 days after second immunization and DTH reaction was determined at 24, 48, 72, and 96 h after administration. Total cell count and cell populations in the bronchoalveolar lavage fluid(BALF), lung associated lymph node(LALN) and spleen weight, special IgG secreted from spleen cells were measured at the end of the experiment. RESULTS: The HC50 of Group 1(47.4 +/- 1.0, 52.2 +/- 4.6, 31.1 +/- 11.9, 43.8 +/- 3.5, 33.6 +/- 16.8, 49.0 +/- 2.3, 92.9 +/- 20.2, 87.7 +/- 5.2) were statistically higher than those of Group 3(40.4 +/- 10.6, 2.8 +/- 2.5, 0.8 +/- 0.6, 6.6 +/- 5.8, 1.4 +/- 0.1, 36.5 +/- 16.5, 53.0 +/- 33.2, 2.6 +/- 2.2). The special anti-SRBC IgG response in Group 1(1.67 +/- 0.19, 1.98 +/- 0.36, 1.12 +/- 0.50, 1.38 +/- 0.30, 2.75 +/- 0.15, 2.60 +/- 0.28, 2.86 +/- 0.10, 2.50 +/- 0.20) were much stronger than those in Group 3 (0.59 +/- 0.30, 0.56 +/- 0.21, 0.21 +/- 0.16, 0.22 +/- 0.01, 0.81 +/- 0.25, 0.74 +/- 0.25, 0.69 +/- 0.26, 1.38 +/- 0.41). Furthermore, the results of DTH showed positive response and the ratios for diameter of skin rash > 5 mm at 24, 48, 72, 96 h were 16/16, 16/16, 16/16, 15/16 respectively in Group 1, while those in Group 3 were 8/15, 1/15, 1/15, 1/15 respectively. Total cell count in the BALF, LALN and spleen weight, and special IgG secreted from spleen cells in Group 1 were higher too. Group 2 expressed almost of the same but with mild immunologic responses as Group 1. CONCLUSION: Silicosis-induced extremely strong DTH and over-response of humoral immunity to some antigens may contribute to the likelihood of silicosis complicated with tuberculosis.